This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from applications for 3-WAY TYPE REFRIGERANT CONTROL VALVE FOR REFRIGERATING CYCLE earlier filed in the Korean Industrial Property Office on the May 29, 2000 and there duly assigned Ser. No. 2000-29050, and for 3-WAY TYPE REFRIGERANT CONTROL VALVE FOR REFRIGERATING CYCLE earlier filed in the Korean Industrial Property Office on the Aug. 29, 2000 and there duly assigned Ser. No. 2000-50444.
1. Field of the Invention
The present invention relates to three-way flow control valves for refrigeration cycles having two parallel heat exchangers and, more particularly, to a three-way flow control valve designed to selectively feed refrigerant to both heat exchangers or one of the two heat exchangers as desired.
2. Description of the Prior Art
As well known to those skilled in the art, a refrigeration cycle typically performs its refrigerating operation through a compression process, a condensation process, an expansion process, and an evaporation process. In a brief description, the refrigerating operation of the conventional refrigeration cycle is accomplished through repeated heat exchanging processes. Such refrigeration cycles have been preferably used in, for example, refrigerators and air conditioners.
In such refrigeration cycles, the compression process is performed by a compressor, the condensation process is performed by a condenser, the expansion process is performed by a capillary tube or an expansion valve, and the evaporation process is performed by an evaporator.
FIG. 1 shows a conventional refrigeration cycle, in which first and second evaporators 1A and 1B are arranged in parallel to each other to respectively cool the partitioned first and second refrigeration compartments R1 and R2 to desired temperatures. First and second capillary tubes 5a and 5B are mounted to the parallel refrigerant passage lines for the two evaporators 1A and 1B at positions before the two evaporators, respectively. First and second solenoid valves 4A and 4B are mounted to the parallel refrigerant passage lines at positions before the two capillary tubes 5A and 5B, respectively, so as to control the refrigerant flow for the two capillary tubes 5A and 5B. The above solenoid valves 4A and 4B are two-way flow control valves that are normally closed.
Provided on the main refrigerant passage line at positions before the two solenoid valves 4A and 4B are a compressor 2 and a condenser 3.
When it is desired to cool the partitioned first and second refrigeration compartments R1 and R2 to desired temperatures at the same time using the conventional refrigeration cycle, both the two solenoid valves 4A and 4B are opened. Therefore, the condensed refrigerant from the condenser 3 partially passes through both the first solenoid valve 4A and the first capillary tube 5A to reach the first evaporator 1A within the first refrigeration compartment R1. The refrigerant within the first evaporator 1A absorbs heat from air within the first refrigeration compartment R1, thus cooling the air to a desired temperature. On the other hand, the remaining part of the condensed refrigerant from the condenser 3 passes through both the second solenoid valve 4B and the second capillary tube 5B to reach the second evaporator 1B within the second refrigeration compartment R2. The refrigerant within the second evaporator 1B absorbs heat from air within the second refrigeration compartment R2, thus cooling the air to a desired temperature.
On the other hand, when it is desired to cool only the second refrigeration compartment R2 to a desired temperature, the second solenoid valve 4B is opened, with the first solenoid valve 4A kept at its closed position. In such an exclusive cooling mode for the second compartment R2, all the condensed refrigerant from the condenser 3 passes through both the second solenoid valve 4B and the second capillary tube 5B to reach the second evaporator 1B, and cools air within the second compartment R2 to the desired temperature. In the same manner, an exclusive cooling mode for the first refrigeration compartment R1 is accomplished by opening the first solenoid valve 4A and closing the second solenoid valve 4B.
However, such a conventional refrigeration cycle is problematic in that it is necessary to provide the two flow control valves for separately controlling the refrigerant flow for the two parallel evaporators, thus increasing the production cost of the refrigeration cycle in addition to increasing operational noise created from the drive unit for the two flow control valves.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a three-way flow control valve for refrigeration cycles having two parallel heat exchangers, which selectively feeds refrigerant to both heat exchangers or one of the two heat exchangers as desired.
In order to accomplish the above object, the present invention provides a three-way flow control valve, comprising a hollow cylindrical casing opened at its first and second ends, a first valve housing held in the first end of the casing and provided with a first refrigerant outlet and a first orifice formed in the first refrigerant outlet, a second valve housing held in the second end of the casing and provided with a refrigerant inlet and a second refrigerant outlet and a second orifice formed between the refrigerant inlet and the second refrigerant outlet, a first valve means axially set within the first valve housing so as to be axially movable to control the opening ratio of the first orifice, a second valve means axially set within the second valve housing so as to be axially movable to control the opening ratio of the second orifice, and an actuation means used for actuating the first and second valve means and set between the first and second valve housings while allowing the two valve housings to communicate with each other.
In the primary embodiment of this invention, first and second guide bores are provided within the first and second valve housings at the inlet ends of the first and second orifices. The first and second guide bores are threaded on their internal surfaces to form internal threads, and guide an opposite directional axial movement of the first and second valve means. Each of the first and second valve means comprises a spring holder set within an associated refrigerant outlet, a needle valve body movably set within each valve housing while axially penetrating an associated orifice, and an elastic biasing member set between the spring holder and the needle valve body to normally and elastically bias the needle valve body in a direction toward the actuation means.
The actuation means comprises a stator externally set around the sidewall of the casing, a rotor rotatably set within the casing with a gap left between the external surface of the rotor and the internal surface of the casing, a rotating shaft axially penetrating the rotor, a first actuator assembled with the upper end of the rotating shaft and axially moving the needle valve body of the first valve means in opposite directions in cooperation with the elastic biasing member of the first valve means and threaded on its external surface to form external threads movably engaging with the internal threads of the first guide bore, and a second actuator assembled with the lower end of the rotating shaft and axially moving the needle valve body of the second valve means in opposite directions in cooperation with the elastic biasing member of the second valve means and threaded on its external surface to form external threads movably engaging with the internal threads of the second guide bore.
In the three-way flow control valve, at least one communication hole is axially formed in each of the first and second actuators, thus allowing the two valve housings to communicate with each other through the communication holes of the two actuators.
In addition, two stoppers are provided at positions around opposite end surfaces of the rotor for limiting upper and lower dead points of the rotor.
Each of the two stoppers comprises a plurality of pin seat holes axially formed on the inside end surface of each valve housing, a stop pin set in one of the pin seat holes of each valve housing, a rotatable disc set on each end surface of the rotor, and a stop projection formed on the outside surface of the rotatable disc at the edge while extending toward the stop pin so as to be selectively caught by the stop pin.
In the three-way flow control valve according to the second embodiment, the first orifice of the first valve housing is formed at the inlet end of the first refrigerant outlet, and directly communicates with the interior of the casing. The first valve means comprises a first spring holder set within the first refrigerant outlet, a first needle valve body movably set within the first valve housing while axially penetrating the first orifice, and a first elastic biasing member set between the first spring holder and the first needle valve body to normally and elastically bias the first needle valve body in a direction toward the actuation means. A guide bore is provided within the second valve housing at the inlet end of the second orifice. This guide bore is threaded on its internal surface to form internal threads and guiding an opposite directional axial movement of the second valve means. The second valve means comprises a second spring holder set within the second refrigerant outlet, a second needle valve body movably set within the second valve housing while axially penetrating the second orifice, and a second elastic biasing member set between the second spring holder and the second needle valve body to normally and elastically bias the second needle valve body in a direction toward the actuation means.
In the second embodiment, the actuation means comprises a stator externally set around the sidewall of the casing, a rotor rotatably set within the casing with a gap left between the external surface of the rotor and the internal surface of the casing, a rotating shaft axially penetrating the rotor, a first actuator assembled with the upper end of the rotating shaft and axially moving the needle valve body of the first valve means in opposite directions in cooperation with the elastic biasing member of the first valve means, and a second actuator assembled with the lower end of the rotating shaft and axially moving the needle valve body of the second valve means in opposite directions in cooperation with the elastic biasing member of the second valve means and threaded on its external surface to form external threads movably engaging with the internal threads of the guide bore of the second valve housing.
The three-way flow control valve according to this second embodiment has two stoppers, which are provided at positions around opposite end surfaces of the rotor for limiting upper and lower dead points of the rotor.